“The nature of the discretion conferred upon directors to refuse registration has been discussed in a number of cases. It must however be borne in mind that not all articles are in precisely the same terms. Some are more restrictive of the matters which the directors may take into account than others. Article 3(a) is framed without any express limitation upon the discretion. In Re Smith & Fawcett Ltd., (1942) 1 All ER 542 at p. 545, (1942) Ch 304 at p. 308; Lord Greene MR said of a similar article : ‘In the present case the article is drafted in the widest possible terms, and I decline to write into that clear language any limitation other than a limitation, which is implicit by law, that a fiduciary power of this kind must be exercised bona fide in the interests of the company.’ The directors are prima facie assumed to have been acting in good faith and the onus of proving the contrary is upon the person who challenges their decision : see Char ....